Grab for use in wells



Aug. 28, 1928.

J. A. CADY GRAB FOR USE IN WELLS Filed Aug. 5, 1926 2 sheets-sheet 1 74 TTORMEK Aug. 28, 192s. Y 1,682,4sr

' J. A. CADY YGRAB FORk USE IN WELLS Filed Aug. 3, 1926 2 Sheets-Sheet 2 2f Z9 lll/,A\\ 57 ffl/@ 2/ @.20 J5 ZZ .22 f /22 62 @/t0 F *i4 30 f' l5 v f/ Z il 34 l, 25 Z4 Lih l l l Il /f40 JJYY/MTOR" l y/ 4Z JOHN A' @ADK j 5f well to remove members lost therein.

Patented Aug. 28, 1928.

UNITED STATES PATENT OFFICE.

JOHN A. oADY, or Los ANGELES, cALiiionNiA.

GRAB FOR USE IN WELLS.

Application filed August `3, 1926. Serial No. 126,820.

This invention relates to grabs or fishing tools employed in the well drilling industry for removing parts which have been lost in the hole being drilled. In the drilling of wellsy it often occurs thereof rbecome'lost in the hole and their presence makes further drilling diilicult. The lost part must be removed, sidetracked or drilled up before the drilling operation can proceed. This invention rclates A portion of a drill bit or a drill pipe which has been twisted off will cause serious trouble at the bottom of a well and therefore much time and laborare expended in an endeavor i pivoted to the' grab members,

to remove such parts from the hole. l

It is an object of this invention to provide a grab whereby a lost part may be removed from the hole with a minimum of time and with a minimum expenditure of labor.

In the ordinary type, of grabs in use today, the lost part being grappled is not gripped until an up movement of the grab tool has started. There is great possibility that a slight relative movement will occur between the grab and the part before the jaws of the grab are caused to firmly engage the part. Because of this, frequently the part will slip V,from position between the jaws and notbe engaged. This requires the grab to be reset and another attempt to catch the lost part.

It is an obj ect of this invention to provide a grab in which the `jaws thereof are caused to securely engage the lost part before any up motion of the grab is commenced.

Another object of the invention is to provide a simplified forni of grab in which there are no interconnected pivoted parts between the tubing, by means of which the grab is but in which the grab members are directly connected to the tubing when moved into gripping en. gagement with a lost part by the drill tubino'.

still further object of the invention is to provide a grab in:which washing fluid may be supplied lost part from the bottom of the well.

Another object is to provide a grab which, after an object `has been firmly gripped thereby,vm`ay be given a jar to loosen the object from the mud and permit it to be drawn to thesurface.' Y' `Other objects and advantages of the invention will be made evident hereinafter.

that tools or portions to tools adapted to be lowcrediinto a for assisting in freeing the .showing'the parts in the positions they oc-` cupy when a lost part has been grabbed.

Fig. L.Lis a section taken on the line 1--4 of Fig. 3.

Fig. 5 is a section taken on the line 5-5 of Fig. 3.

Fig. 6 is a section taken on the line 6-6 of Fig. 2.l v

Referring to Fig. 1, the numeral 11`represents a partly drilled well in which a lost part 12 has been lodged. This part may have been lost .by an uncoupling of a joint or by a twist-off or breakage of a tool. At the upper end of the well 11 is a rotary machine 13 through which a tubing 14 is extended into the well. At the lower end of the tubing 14 is a grab`16 embodying the `features of the invention. v

split shell which provides a cylindrical chamber 21. For the purpose of making convenient the assembling ofthe grab, the

shell 2O is composed of two semi-cylindrical members 22. The lower ends of the meinbers 22l are threaded as indicated at 23, and y a lower collar. 24 is screwed thereon, thus clamping the lower ends tightly in the position shown inthe drawings. The upper ends of the members 22 are` threadedas indicated at 26 and an upper collar 27 is screwed thereunto for rigidly clamping the upper ends of the members 22 together. The lower end of the tubing 1-1e2 tends through a slide bearing opening 29 formed in the upper collar 27and a bottom coupling 30 is secured to the lower end thereof, the bottom coupling being locates. inside the chain-v ber' 21. The grab 16 is supported at the lower endof the tubing '14. by engagement of the upper collar 27 with the bottom coupling 30.

Immediately above the lower end of the shell 20 is formed an internal annual groove 33 which is formed in a horizontal plane, and which is substantially se'mi-cylindrical in cross section. An annular recess 34 is formed in the lower part of the shell 2O above the aiinlilaigioove 33. The recess 3l, as illustrated in Figs. 2 and 3, is frusto-conical so that the upper end thereof is deeper than the lower end thereof. 1

Carried at the lower end of the shell are grab members In the drawings I have shown only a pair of grab members, but itshould be understood that more in ay be provided withoutdeviating from the 1nvention. rI`he grab members 35 have inner and outer areuated faces 3G and 37. Formed on the outer faces 3G of the grab members slightly above the middle are pivot lugs 3S which have semi-cylindrical faces and which rest in the annular groove 33 as shown in Figs. 2, 3 and G. The grab members are pivoted to the shell 2() by means of the pivot lugs 38 and the annular groove 'lhe portions of the grab members 35 below the pivot lugs 33 constitute jaws lel() having jaw teeth lll formed at the lower ends therof. The jaw teeth itl are provided with upper horizontal faces and lower diagonal faces as shown.A The portions of the grab members 35 extending above the pivot lugs 38 constitute operating arms il2 and are provided with teeth 43 having upper diagonal faces and lower horizontal faces.

The grab members 35 are semicylindrieal only in the plane of the pivot lugs 38 and therefore edge faces 44 of the grab members 35 contact in this plane. The faces 411-, however, spread away from each other as the opposite ends of the grab members are approached so that the grab members Vare less than semi-cylindrical at all points with the exception of the portion at the plane of pivot thereof. The faces 44, where they engage, form rocking bearings and hold the grab members outward so that the pivot lugs 38 are in proper pivotal engagement in the annular grooves 33. The grab members 35 are formed, as shown, so that they may pivot relative to each other and pivot relative to the shell 2l). It will be seen that if the edge faces all were parallel and in engagement along their entire length there could be no relative pivotal movement between the grab members.

Extending inward from the inner faces 37 of the grab members slightly below the pivot plane thereof are stop flanges 4G which are adapted to prevent the lost part 12 from extending upward into the grab members beyond the position in which it is shown in Fig. 3. p

Positioned in Vthe upper end of the chamber 21 of the shell 20 is an engager 49. The upper end of the engager 49 is provided with a threaded pin 50, by means of which it is connected to the bottom coupling secured to thelower end of the tubing 14. The engager 49 has a body 5l which is frustolconical, being smaller at its lower end.

such that the engager The body 5l is provided with a multiplicity of annular teeth 52 which are arranged in a horizontal plane. The upper faces of the teeth 52 arehorizontal, whereas the lower facespthereof are diagonal as illustrated.

Extending through an opening in the engager @t9 is a wash pipe 55, the lower cnd of the vash pipe 55 projecting ay distance below the lower end of the engager A stalling box 57 is provided at the upper end of the engager' 49, surrounding' the wash pipe 55 for the purpose of preventing :l leakage from the inside ofthe tubing ll around the wash pipe 55. 'I'be upper part of the wash l)ipe 55 extends inside the tubing ll and through a couplingr 53 which is placed in the tubing 14; a short distance above the lower end thereof. A. washer GO is rigidly secured to the wash pipe 55 directly above the engager I9 and a loose washer (il is placed on the top of the pipe 55 below a coupling 58. Impressed between the washers G() and Gl is ay spring (52. The spring G2 is provided for the purpose of resiliently holding the wash pipe 55 in the position shown in the drawings. If rthe lower end of the wash pipe 5:5 engages vthe part l2 being grapplcd, no injury will occur thereto, but it will be moved upward against the action of the spring (52.

The operation of the invention is substantially as follows:

The grab members normally rest in the position shown in Figs. l and 2. The points of pivot of the grab members, as illustrated in Fig. Q, are outside the circmnferencc of the grab members; therefore, the tendency is for the lower ends to swing outward until the center of gravity of them is below the centers of pivot. During the lowering of the grab 16, the parts are in the j'iositions shown in Figs. l and 2, the grab being supported by the bottom coupling 30 which is secured to the lowerend of tbe tubingr 14.

In Fig. 2 the grab is shown lowered to the extent that the jaws have surrounded the part 12. IVhen the upper end of the part l2 which is represented by dotted lines 47 in Figs. 2 and 3 engages the stop flanges 4.6, the shell 2O and the grab members 35 will be stopped from movement by the tub- 'mg ll and the engager 49 will continue to move downward, there being a. relative movement between the shell and grab members and the tubing and engager. `The engager 49 moves downward and passes inside `the operating arms 42 of the grab members 35, spreading them outward as shown in Fig. 3. The operating arms may or may not be swung into the recess 33, this depending upon the distance that they are swung outward. The engager 49 is coni -al and therefore easily enters between the operatinfr arms 42. The faces of the teeth 43 and o2 'are maybe lowered. The

jaws move inward into the position shown in Fig. 3, so as to tightly grip the lostpart 12. It should be noted that the entire weight of the tubing 14 is applied in forcing the engager 49 between the operating arms 42. This Weight is sufficient to cause the jaw teeth 41 to partially imbed themselves in the outer faces of the lost part. l

In order to assist in freeing the lost part, Washing fluid can be delivered to the upper end of the lost part through the Wash tube 55. If the lower end of the wash tube engages the upper end of the lost part, it will merely move upward relative to the engager and tubing without doing any damage. i

After the lost part has been securely engaged, as shown in Fig. 3, the tubing'14 is raised. The horizontal faces of the teeth 43 and 52 of the operating arms and the en-V gager respectively are in engagement and therefore the engager 49 cannot be removed from the position shown in Fig. 3. The jaw teeth 41 have upper horizontal faces, as previously explained, and therefore cannot lose their grip on the part 12. The lift on the part 12 is transferred from the tubing 14 directly through the engager 49 and the rab members 35, It is absolutely impossible for the jaw teeth 41 to lose their grip on the pipe 12 while the engager 49 is in position inside the operating arms 42 and holding them outward as shown in Fig. 3.

A very important part of the invention is that the jaw teeth 41 are caused to securely. grab the lost part before any upward movement of the grab 16 is started. This is desirable because of the fact that there is no danger of the part slipping from place when an up movement is initiated. Another important feature of the invention is the fact that the grab members 35 are engaged by the engager 49 which is rigidly secured directly to the lower end of the tubing 14. The construction of the invention is of utmost simplicity and consequently the parts may be ma e very rugged so as to endure great strains and have long life. The wash pipe 55 Ihaving its resilient mounting is very important to the invention since it is very helpful in freeing the lost part from the bottom of the hole by washing the material away which has packed therearound.

One of the important features of my invention is that after the teeth 41 are imbedded in the surface of the lost part 12, the tubing 14 may be lowered a slight distance and then gager 49 to come into sudden engagement with the teeth 43, thus transmitting an upmembers lifted suddenly causing the en said tubing for supportingl said grab members; an engager' attached directly to said tubing and being adapted to engage said grab members, thus causing them to grab a lost part, said lost part being lifted by means of said tubing,`said engager, and said grab members; and a wash pipe extending from said tubing through said engager and inside said grab members.

2, A grab` comprising: a tubing; grab members; a shell carried at the lower end of said tubing for supporting said grab menibers, said shell enclosing the upper ends of said grab members; an engager attached di# rectly to said tubing and located in said shell, said engagei beingadaptedto engage said grab members, thus causing them to grab a lost part, said lost part being lifted by means of said tubing, said engager, and said grab members; and a Wash pipe extend ing from said tubing throngh said engager and inside said grab members.

3. A grab comprising: a tubing; grab members; means carried at the lower end of said tubing for supporting said grab members; an engager attached directly to said tubing and being adapted to engage said `grab members, thus causing Athem to grab a lost part, said post part being lifted by means of saidtubing, said engager, and

said grab members; mounted wash pipe extending from said tubing through said engager and inside said grab members.

4. rA grab comprising: a tubing; grab of saidtubing for supporting said grab members, said shell enclosing the upper ends of said grab members; an engager attached directlyto said tubing and located in said,

shell, said engager being adapted to engageV said grab members, thus causing them to grab a lost part, `said lost part being lifted by means of said tubing, said engager, and said grab members; and a resiliently mounted wash pipe extending from said tubing through said engager and inside said grab members.

In testimony whereof, I havel hereunto set my hand at Los Angeles, California, this 29th day of July, 1926. Y Y JOHN A. CADY.,Y

and Va resiliently a shell Vcarried at the lower end i 

